A plunger type hay baler includes a frame that is hitched to a tractor and is configured to receive crop material, such as hay or straw, into a pressing cavity in which the crop material is pressed and formed into a bale. The baler includes a loading mechanism in which the crop material is collected from the ground, which is then routed into the pressing channel in a manner that is synchronous with a plunger. The plunger moves in a reciprocating manner in the pressing channel and encounters each new segment (flake) of crop material that is moved into the channel for compacting into a bale. After a sufficient amount of crop material has been compressed in the pressing channel, a twine threading mechanism inserts twine through a portion of the compressed material and the twine is then tied to complete the binding of the bale. The bale then proceeds further through the pressing channel and is ejected from the baling machine.
The shape of the bale in a baling device is important in determining the appropriate length of the bale and rectangularity for the purpose of storing, stacking and transporting. Current systems attempt to determine bale shape and length by sensing pressure forces that are reaction forces exerted against the plunger, and associated mechanism used to compress the flakes. When the force exceeds a given level, the bale is determined to be an appropriate length and then the subsequent processes are initiated.
The problem with this device, however, is that the pressure sensing to determine length of the bale does not occur until the last group of flakes enters the channel in which they are compressed. As a result, flakes can be entered into the chamber that have variable thickness from side to side so that instead of rectangular flakes forming the ultimate bale there may be misalignment between one side and the other. Such a malformation can have an impact on the ability to stack the resulting bales and/or to transport them.
Accordingly, what is needed in the art is a means and method for dynamically and effectively sensing the shape of a bale with an accurate measurement.